E-mail this article

Sending your article

Your article has been sent.

WINTER PARK, Fla. – The Big Three is officially a memory because Ray Allen is headed to South Beach.

Late Friday night, Allen agreed to join the Miami Heat on a three-year contract, according to NBA sources. Heat owner Micky Arison let the NBA world know of the news through Twitter, making Allen’s departure from the Celtics painfully official.

NBA players cannot officially sign new contracts until the moratorium ends July 11.

Allen will go to Miami for half the money the Celtics were offering, choosing the better weather, the chance to play with LeBron James and Dwyane Wade, and a fresh start with a new team.

Allen was unhappy during his final season in Boston, again placed on the trading block because of his expiring contract. He was forced to approach coach Doc Rivers about moving to the bench when second-year guard Avery Bradley began to blossom as a defensive force.

The Celtics attempted a late run at Allen, offering $6 million per season for two years and promising a more defined role. But the signing of Jason Terry, another 3-point marksman, clouded Allen’s status.

On Thursday, Allen met with Heat president Pat Riley, coach Erik Spoelstra, and team executive Alonzo Mourning, but left without agreeing to a contract. He returned to Boston Friday and informed the Heat of his decision in the evening.

For the Celtics, it marks the end of the Big Three of Paul Pierce, Kevin Garnett, and Allen, who joined forces in 2007 and won an NBA title in 2008, lost in the seventh game of the 2010 Finals, and reached the Eastern Conference finals just this year against the Heat.

Allen only started in the Heat series because Bradley was out because of shoulder surgery. Allen played with bone spurs in his right ankle, limiting his effectiveness. Allen underwent surgery to remove the spurs and the Celtics believed he would be ready to begin the season.

Danny Ainge told the Globe last Sunday that Allen’s return was his No. 1 priority after Kevin Garnett agreed to a three-year deal to return. But by then, Allen was considering other options. His meeting with the Los Angeles Clippers was canceled when they agreed to terms with Jamal Crawford, leaving the Heat as the Celtics’ primary competition for Allen.

With Mike Miller a likely candidate to have his contract removed with the amnesty clause, the Heat were in search of another shooter. James publicly lobbied for Allen.

The Big Three Era was one of the grandest in Celtics’ history, starting the trend of three All-Stars coming together to attempt to win a championship. With Garnett’s grit, Pierce’s midrange stroke, and Allen’s long-range prowess, the Celtics instantly became one of the top teams in the NBA.

It appeared after this season’s Game 7 loss to the Heat that the era was over, but Garnett re-signed and Ainge made the decision to reload.

But one of those reloading decisions was to sign Terry to a three-year deal, and Bradley is expected to come back healthy in perhaps December, leaving Allen to ponder whether his situation would improve.

In 358 regular-season games with the Celtics, Allen averaged 16.7 points and canned 798 3-pointers. His best season with the Celtics was 2008-09, when he averaged 18.2 points.

Allen was the Celtics’ best player during the first six weeks of last season, but the team struggled in the first half. When he missed six games in March/April with a sore ankle, Bradley flourished as his replacement. Finally, before an April 5 game at Chicago, Allen approached Rivers about coming off the bench.

According to those close to Allen, he was not happy with Bradley being given such an increased role. Allen was uncomfortable with his role off the bench, telling those close to him that he wasn’t the instant offense type of player, such as Terry, Crawford or Vinnie Johnson.

Also, Allen had a increasingly difficult relationship with Rajon Rondo, who supported Bradley in the starting lineup because of his defensive prowess. Allen told the Globe several times he was unhappy not being established early in games, then asked to save the Celtics with 3-point shooting in the fourth quarter.

His shot attempts decreased to 10.7 per game this season compared with 13.5 in his first season and 12.2 per game in 2010-11. It became apparent his ankle was a major factor as the season progressed. He shot 48.5 percent from the 3-point line in the first 28 games and that number deceased to 41.2 percent in the final 18 games of the regular season.

. . .

So far, Jared Sullinger’s back issue is a non-issue.

The burly forward-center has participated in all of the Celtics’ summer league practices, including Friday at Rollins College, and he said the back injury that apparently scared lottery teams from taking him has not been any concern. He plans to play for the Celtics in both the Orlando and Las Vegas Summer leagues.

“I’m fine, but it is what it is and people are going to say what they say,” he said. “I don’t know what it is. They haven’t told me I can’t play in games.”

Sullinger joined his teammates as they arrived in Florida in preparation for their summer league debut Monday against the Oklahoma City Thunder. The roster includes Sullinger, fellow first-round pick Fab Melo, and second-round pick Kris Joseph.

Second-year players JaJuan Johnson and E’Twaun Moore are also on the club, along with former training camp invitee and UMass standout Stephane Lasme, who nearly made the club two years ago but was beaten out by Von Wafer.

. . .

Restricted free agent center Greg Stiemsma will meet with the Timberwolves Saturday . . . There has been little contact between the Celtics and free agent Mickael Pietrus, who has said he wants to come back to Boston. The re-signing of Jeff Green seems to have made Pietrus expendable, and the Celtics filled their void for 3-point shooting off the bench by agreeing to a three-year contract with Terry.